Known among curable organopolysiloxane compositions, which are comprised an organopolysiloxane having in one molecule at least two silicon-bonded lower alkenyl groups, an organopolysiloxane having in one molecule at least two silicon-bonded hydrogen atoms, and a hydrosilylation-reaction catalyst, and which demonstrate excellent self-adhesion to various substrates as a result of curing, are curable organopolysiloxane compositions that contain an organosilicon compound having in one molecule a silicon-bond-unsaturated group and a silicon-bonded alkoxy group, an organosilicon compound having in one molecule a silicon-bonded hydrogen atom and a silicon-bonded alkoxy group, an organosilicon compound having in one molecule a silicon-bonded epoxy group and a silicon-bonded alkoxy group, or an aluminum compound, zirconium compound, titanium compound, or a similar adhesion-promotion agent (refer to Japanese Laid-Open (Unexamined) Patent Application Numbers Sho 63-30562 (30,562/1988) and Hei 4-246466 (246,466/1992)).
However, the aforementioned curable organopolysiloxane compositions demonstrate insufficient adhesion at low temperatures to substrates such as PPS resins and aluminum die castings with unclean surfaces.
It is an object of the present invention to provide a curable organopolysiloxane composition that shows good adhesion to substrates such as PPS resins and aluminum die castings with unclean surfaces, even at relatively low heating temperatures such as 100° C.